Hand brake mechanism



Nov. 30, 1937. R. c. O'CONNOR HAND BRAKE MECHANISM Filed Dec. 26, 1935 2Sheets-Sheet l Nov. 30, 1937. R. c. OCONNOR 2,100,349

HAND BRAKE MECHANISM Filed Dec. 26, 1935 2 Sheets-Sheet 2 Pate ed Nov.30, 1937 UNITED STATES PATENT OFFICE HAND BRAKE MECHANISM ApplicationDecember 26, 1935, Serial No. 56,183

' 4 Claims.

The present invention is directed to a hand brake for railway cars,which makes provision for quickly and easily taking up the slack in thebrake rigging, and the invention relates particularly to theconstruction and arrangement of the winding drum and its relation to theassociated gear and also the pawl and ratchet mechanism and the handlever for actuating the same.

Further objects and details will appear from a description of theinvention in conjunction with the accompanying drawings, wherein- Figure1 is a front elevation of the brake mechanism showing the hand wheelpartly broken away;

Fig. 2 is a sectional elevation taken on line 2 of Fig. 1;

' Fig. 3 is a similar section taken on the same line showing a modifiedform of drum and brake chain; and

120 Figs. 4, 5, and 6 are details showing the pawl .25 front cover plateH), a rear wall ll, end walls I2, and an arched over top wall l3. Theend walls and top wall are formed integrally with the rear wall, and thefront plate is secured thereto by rivets 14 or other suitable fasteningmeans.

.30 The front cover plate, as shown, is provided with an outwardlyextending protuberance 15 in its lower portion, of arch-shapedconfiguration, and in the center of said protuberance the metal isoutwardly bulged to afford a center boss I6 35 which receives theforward end of a gear wheel axle I! provided with a flanged head l8which fits into a, recess l9 formed in the inwardly protruding boss onthe rear wall it of the frame. The front end of the axle extends beyondthe 40 plane of the inner face of the protuberant lower portion of thefront plate and abuts against the inner face of the boss l6, being heldin place by a cotter .pin 2| or other suitable fastening. The axle I! issurrounded by a forward bushing 22, a

45 rear bushing 23, and an intermediate bushing 24. The forward andintermediate bushings are provided at their outer ends with flangeswhich in conjunction abut against the ends of the hub 26 of a windingdrum 2'! which is journaled upon 50 the bushings. The forward bushing 22abuts against a bridge plate 22 which spans the space across theprotruding boss I6 and has its ends integrally formed with the end wallsof the frame. This arrangement brings the forward and '55 rear ends ofthe shaft ll into direct alignment with supports which are integrallyformed in the frame so that a very rigid and rugged construction isprovided and the shaft is accurately aligned within integrally formedportions of the frame.

The winding drum is provided with a bifurcated web portion 28 furnishinga groove or channel 29 flanked on either side by the smooth cylindricalfaces 30 of the periphery of the drum, which configuration affords awinding surface for the alternatelinks 3| of a brake chain, the in- 10termediate links 32 standing in transverse relation and in position toenter the center groove or channel 29 in the winding drum, so that asthe chain is wound up, the alternate links will lie flatwise upon thedrum surface with the inter- 15 mediate links standing edgewise withinthe groove.

The bushing 23 furnishes the bearing for a gear wheel 33 having a web34, a hub 35, and a toothed rim 36.- The web is provided at a suit- 20able point with a forwardly projecting boss 31 provided with a bore 38to receive a headed bolt 39 which extends through a hardened collar 40which furnishes an anchorage for the terminal link of the brake chain,the anchorage being in alignment with the plane of the groove in thewinding drum.

The teeth of the gear wheel 33 mesh with pinion teeth 4| on a hand wheelshaft 42, the forward portion 43 of which projects through an aperture30 44 in the front cover plate Ill. The forward portion 43 of the shaftis squared and tapered and terminates in a threaded stem 45 enteredthrough a square tapered bore 46 in the hub 41 of a hand wheel 48. Thehub as shown is inwardly elongated and provided with a square bore inits center portion 49 to clear the surface of the square tapered portionof the shaft. The forward end of the hub, however, is provided with asquare tapered bore 50 which aligns with a square a) tapered bore 5| atthe inner end of the hub, so that these two portions of the hub willcome into wedging contact with the surface of the square tapered shaft43, being held in clamped relation thereon by a nut 52 threaded onto thestem 45. 45 The shaft 42 in advance of the gear teeth 4| is enlarged toafford a ratchet wheel 53 having ratchet teeth 54 of saw-toothformation. Between the ratchet wheel portion of the shaft and the squaretapered portion, the shaft is cylindrical- 50 1y formed to afford abearing surface 55 working within a bushing 56 which cooperates with arear bushing 51 housed in a boss 58 in the rear wall to afford separatedbearing surfaces for the hand Wheel shaft. 55

The ratchet 53 coacts with a pawl 59 having a tooth 60 positioned toengage with the abrupt faces of the ratchet teeth, and the pawl iscarried by a hub 6| provided with a center axial bore 62. The hub at itsinner end is provided with an inwardly protruding segmental stop 63extending through approximately 120, the ends of which furnish stops forengagement with the ends of a segment 64 formed on or rigidly secured toa coaxial handle shaft 65 upon which the pawl hub is pivotally mountedfor limited rotation. The handle shaft at its forward end carries ahandle 66 which extends beyond the cover plate and frame, as shown inFig. 1, and terminates in a weighted end portion 68. The hub BI isprovided with a counterweight 69, which assists in the release of thepawl tooth 60. The relationship of the handle shaft 65 with its segment64 to the segmental stop 63 is one which permits the handle shaft tobeturned freely through approximately 120 before the end of the segment 64abuts against the inner end of the pawl stop 63.

The bushing 55 is carried by a boss 10 formed in a plate H which isriveted to the end walls of the frame and lies in abutting relation tothe inner face of the front cover plate when the parts are assembled.

With the pawl in engagement with the ratchet teeth as in Fig. 4, theweighted handle 66 will lie in a position below the horizontal, and thecontact of the forward end of the segment 64 with the outer end of thesegmental stop 63 will serve to hold the pawl in engaged position. Asthe handle is lifted and turned beyond its vertical position, as in Fig.5, the rear end of the segment 64 will engage with the inner end of thesegmental stop 63, and further movement will cause the disengaging ofthe pawl tooth from the ratchet wheel.

The rearward movement of the handle 66 is limited by a tooth 12 at thebase of the handle which is adapted to abut against the stop 13 on thewall of the frame. The arrangement is one which permits the handle to bedrawn freely upward and past the medial position without encounteringany resistance, so that it is possible toeffect av hammering actionagainst the pawl segment 63, which may be highly desirable in caseswhere from freezing or other cause there is a tendency for the pawltooth to lock with the ratchet wheel.

As shown in Fig. 6, after the pawl tooth has been carried clear of theratchet teeth by the thrust of the handle 56, it will be swung furtheroutwardly by the counterweight 69 until the pawl strikes the wall of theframe, which limits its outward movement.

The pawl is held in mesh with the ratchet in the on position by theweight of the release handle, and this arrangement enables a brakeman toforce the pawl into engagement with the ratchet by pressing down on thehandle in case the pawl should stick while in the off position. Inreleasing the brake, the handle is thrown about 40 past the verticalcenter line, and in normal operations the operator will then turn thebrake wheel sufiiciently to take the strain off the pawl, which allowsthe handle to drop farther to the right and disengage the pawl from theratchet. However, if difliculty is encountered in effecting the release,force may be applied to effect disengagement of the parts in the mannerdescribed.

The winding drum is separable from the gear wheel and removably mountedon the gear wheel axle, and being round affords a constant pull on thebrake chain from the time the chain comes in contact with the drumsurface until the full takeup of the chain is completed. The windingdrum rotates independently of the gear and will start to rotate when thechain comes into contact with the winding drum, and being removable canbe interchanged for other drums of different diameter to suit the amountof chain to be taken up and the power required. The free rotation of thewinding drum tends to reduce friction and facilitates the full releaseof the brake.

The gear 33 and the winding drum 2'! in conjunction fill the spacebetween the front and rear walls of the frame and serve to reinforce thesame from within and thus prevent the front and rear walls from beingbent inwardly while the cotter pin and the flanged head 18 on the shaftI! give to the shaft itself the characteristics of a rugged tie rod toprevent spreading of the walls outwardly.

The ratchet shaft with the pinion teeth thereon, as Well as the pawl andpawl release handle, are journaled in the rear wall of the frame, andthe front ends are journaled in 'a plate secured to the frame in themanner described, so that with the parts thus assembled the workingmechanism throughout will be accurately aligned and held againstdisplacement irrespective of the cover plate which simply performs thefunction of a closure for the frame and the working parts whichconstitute a self-contained unit.

Fig. 3 illustrates a modified form of winding drum 14 which is providedwith a wide groove 15 so that each link of the chain will fit therein asit is wound around the drum. The chain end may be suitably connected tothe gear 33 as by a bolt 16.

The invention is one which permits the operating parts to be reduced innumber to a minimumand to be fitted and assembled in a manner which willafford great strength and rigidity, with adequate reinforcements at allpoints against distortion or displacement.

Although the invention has been described with particularity as todetail, it is not the intention, unless otherwise indicated, to limitthe invention strictly to the mechanism in the form shown, sincemodifications therein may be made without departing from the spirit ofthe invention.

I claim:

1. In hand brake mechanism, the combination of a frame provided with aremovable cover plate, a gear shaft extending transversely and supportedwithin the frame, a gear wheel, and a winding drum independently mountedupon the shaft and individually rotatable with respect to one another, abrake chain, anchoring means on the gear wheel for the end of the brakechain in position to carry the chain around the drum, and a handoperated gear mechanism for operating the gear wheel.

2. In hand brake mechanism, the combination of a frame provided with aremovable cover plate, a gear shaft extending transversely and supportedat its front and rear ends within integrally formed portions of theframe, a gear wheel, and a winding drum independently mounted upon theshaft and individually rotatable with respect to one another, a brakechain, anchoring means on the gear wheel for the end of the brake chainin position to carry the chain around the drum, and a hand operated gear'mechanism for operating the gear wheel.

tion of a frame having an integrally formed rear wall and end Walls withan integrally formed bridge plate extending across the front of theframe between the end walls, a gear wheel shaft supported at its endswithin the rear wall and the bridge plate and provided with removablemeans for preventing longitudinal movement of the shaft within itsmountings, a gear wheel, and a separate winding drum mounted upon theshaft and independently rotatable with respect to one another, a brakechain having its end anchored to the gear wheel and adapted to becarried around the winding drum by the rotation of the gear wheel, afront cover plate secured to the frame and overlying the bridge plateand the end of the gear wheel shaft, and a. hand wheel and gear teeth inmesh with the teeth of the gear wheel.

4. In hand brake mechanism, the combination of a frame having anintegrally formed rear wall and end walls with an integrally formedbridge plate extending across the front of the frame between the endwalls, a gear wheel shaft removably supported at its ends within therear wall and the bridge plate and provided with removable means forpreventing longitudinal movement, a gear wheel and a winding drumindependently mounted upon the shaft and freely rotatable with respectto one another, a brake chain having its end anchored in position topermit it to be carried around the winding drum by the rotation of thegear wheel, a front cover plate removably secured to the frame andoverlying the bridge plate and the end of the shaft, and a hand wheeland gear teeth in mesh with the teeth of the gear wheel.

RAYMOND C. OCONNOR.

